Week 9: Asthma and COPD Flashcards
asthma
Asthma is a chronic respiratory condition associated with airway inflammation and hyper responsiveness causing reversible obstruction of the airways. Acute asthma involves:
- Bronchospasm (smooth muscle spasm narrowing airways).
- Excessive production of secretions (plugging airways).
RF for asthma
- Personal/familial history of atopy
- Inner city environment
- Obesity
- Viral infections in early childhood
- Smoking
protective factors for asthma
- Vaginal birth
- Increasing sibship
triggers for asthma
e.g. exercise, allergen, irritant exposure, change in weather and viral resp infection- cause an inflammatory cascade within the bronchial tree
presentation of asthma
- Wheeze, shortness of breath, chest tightness, cough
- Symptoms worse at night and in early morning
- Symptoms present in response to exercise, allergen exposure and cold air
- Symptoms present after taking aspirin or beta-blockers or NSAIDs(ask about new drugs)
- History of atopy e.g. eczema and hay fever
- Low FEV volume (FEV:FVC ratio <70%)
- Aggravating factors for attack
- Cold symptoms I.e. UTRI
- Cold air
- Exercise
- Cig smoke/ pollution
- Allergens
diagnosis of asthma
clinical assessment
diagnostic test
clinical assessment in the diagnosis of asthma
- History of recurrent episodes (attacks) of symptoms, ideally corroborated by variable peak flow when symptomatic and asymptomatic.
- Symptoms of wheeze, cough, breathlessness and chest tightness that vary over time.
- Recorded observation of wheeze heard by a healthcare professional.
- Personal/family history of other atopic conditions (particularly atopic eczema/dermatitis, allergic rhinitis).
- No symptoms/signs to suggest alternative diagnoses.
diagnostic tests
should be done when patient is asymptomatic vs symptoms
e. g. peak flow
e. g. spirometry
e. g. FeNO
e. g. CXR
diagnosing children under 5 with asthma
Children under five or those unable to perform objective tests- use clinical judgement based on positive objective test results and presentation to determine likelihood of asthma
DD for asthma
- Bronchiolitis à in very young children
- GORD- can cause cough on lying down
- inhalation of foreign object
- Croup (inspiratory stridor)
complications of asthma
- Pneumonia
- Pneumothorax
- Resp failure and arrest à see medicine block management
ollow up for asthma
annually and risk of asthma attack assessed
FVC
The volume breathed out during the forced expiration.
FEV1
The volume breathed out during the first second
FEV1/FVC
The proportion of the FVC that is breathed out in the first second
PEFR
The Peak Expiratory Flow Rate – the gradient of the graph at time 0, which corresponds to the highest rate of flow of air from the lungs.
spirometry
- Preferred over Peak flow- can be used for initial confirmation of asthma
- Calculates FVC and FEV1
- Can also confirm reversibility in subjects with pre-existing obstruction of airway (after use of bronchodilator)
eak flow
- Measures peak expiratory flow rate
- Simplest test
- Important role in management of established asthma
interpretation
- Patients peak flow can be compared with listed normal for their age, sex and height
- Patients record peak flow diary – can provide objective warning of clinical deterioration
peak flow technique
- Advise the patient to take in a deep breath and expel it as rapidly and as forcefully as possible into the meter.
- The very first part is all that matters for this test and it is not necessary to empty the lungs completely.
- Record the best of three tests. Continue blows if the two largest are not within 40 L/minute, as the patient is still acquiring the technique.
FeNO
- Measure amount of nitric oxide in breath
- Increased levels related to lung inflammation and asthma
- affected by smoking and inhaled corticosteroids
CXR
- Normally normal even in severe asthma
- Not used routinely in assessment of asthma
- Could be used with atypical history/exam
4 principles of asthma management
- Control symptoms
- Prevent exacerbation
- Achieve best possible lung functions
- Minimise side effects
stepwise approach to asthma
-
Step 1 (mild, intermittent asthma)
- Salbutamol (Beta 2-agonist)
- Everyone offered and should be used PRN
-
Step 2 (if use of salbutamol more than 3 times a week, symptoms more than 3 times a week, waking due to asthma more than once a week)
- Inhaled corticosteroid
-
Step 3 (if Beta-2 agonist/ inhaled steroid not enough)
- Add on:
- Leukotriene receptor antagonist (LTRA) before treatment with a long acting beta 2 agonist (LABA)
- LABA should never be used without concurrent use of inhaled steroid
-
Step 4 (persistent poor control)
- Add beclomethasone
- And/or theophylline or beta2-agonsit tablet
-
Step 5
- Continuous or frequent use of oral steroids, maintaining high dose inhaled steroids
- (Referral to resp doctor at step 4-5)
- Omalizumab- option for treating severe persistent allergic IgE mediated asthma
first step in treating asthma
get on SABA e.g. salbutamol
step 2 in asthma mangement
low dose ICS
e.g. prednisolone